Russian President Vladimir Putin thanked North Korea for supporting his actions in Ukraine and said their countries will cooperate closely to overcome U.S.-led sanctions as he headed to Pyongyang on Tuesday for a summit with North Korean leader Kim Jong Un.

Putin’s comments appeared in an op-ed piece in North Korean state media hours before his expected arrival for a visit through Wednesday as the countries deepen their alignment in the face of separate, intensifying confrontations with Washington.

In the North Korean capital of Pyongyang, the streets were decorated with Putin’s portraits and Russian flags. A banner hung on a building said: “We warmly welcome the President of the Russian Federation.”

Putin, who will be making his first trip to North Korea in 24 years, said he highly appreciates its firm support of his military action in Ukraine. He said the countries would continue to “resolutely oppose” what he described as Western ambitions “to hinder the establishment of a multipolar world order based on justice, mutual respect for sovereignty, considering each other’s interests.”

The Kremlin’s forces launched a full-scale invasion of Ukraine in 2022.

Putin also said Russia and North Korea will develop trade and payment systems “that are not controlled by the West” and jointly oppose sanctions against the countries, which he described as “illegal, unilateral restrictions.”

North Korea is under heavy U.N. Security Council economic sanctions over its nuclear weapons and missile programs, while Russia is also grappling with sanctions by the United States and its Western partners over its aggression in Ukraine.

Putin said the countries will also expand cooperation in tourism, culture and education. Before heading to North Korea, Putin traveled to Yakutsk, a city in eastern Russia, where he met regional Gov. Aisen Nikolayev, and received briefings on technology and defense-related projects. He also met with young professionals working in Russia’s Far East.

Putin is being accompanied by several top officials, including Deputy Prime Minister Denis Mantrurov, Defense Minister Andrei Belousov and Foreign Minister Sergey Lavrov, according to his foreign policy adviser, Yuri Ushakov. He said a number of documents will be signed during the visit, possibly including an agreement on a comprehensive strategic partnership.

Putin’s visit comes amid growing concerns about an arms arrangement in which Pyongyang provides Moscow with badly needed munitions to fuel Russia’s war in Ukraine in exchange for economic assistance and technology transfers that would enhance the threat posed by Kim’s nuclear weapons and missile program.

U.S. and South Korean officials say military, economic and other exchanges between North Korea and Russia have sharply increased since Kim met Putin in September in the Russian Far East, their first since 2019.

U.S. and South Korean officials accuse the North of providing Russia with artillery, missiles and other military equipment for use in Ukraine, possibly in return for key military technologies and aid. Both Pyongyang and Moscow deny accusations about North Korean weapons transfers, which would violate multiple U.N. Security Council sanctions that Russia previously endorsed.

Along with China, Russia has provided political cover for Kim’s continuing efforts to advance his nuclear arsenal, repeatedly blocking U.S.-led efforts to impose fresh U.N. sanctions on the North over its weapons tests.

In March, a Russian veto at the United Nations ended monitoring of U.N. sanctions against North Korea over its nuclear program, prompting Western accusations that Moscow is seeking to avoid scrutiny as it buys weapons from Pyongyang for use in Ukraine. U.S. and South Korean officials have said they are discussing options for a new mechanism for monitoring the North.

Earlier this year, Putin sent Kim a high-end Aurus Senat limousine, which he had shown to the North Korean leader when they met in September. Observers said the shipment violated a U.N. resolution banning the supply of luxury items to North Korea.

John Kirby, spokesperson of the U.S. National Security Council, said the deepening relationship between Moscow and Pyongyang is concerning, “not just because of the impacts it’s going to have on the Ukrainian people, because we know North Korean ballistic missiles are still being used to hit Ukrainian targets, but because there could be some reciprocity here that could affect security on the Korean Peninsula.”

“We haven’t seen the parameters of all of that right now, certainly haven’t seen it come to fruition. But we’re certainly going to be watching that very, very closely,” he said.

Lim Soosuk, spokesperson of South Korea’s Foreign Ministry, said Seoul has been stressing to Moscow that any cooperation between Russia and North Korea must not “proceed in a direction that violates U.N. Security Council resolutions or undermines peace and stability in the region.”

Tensions on the Korean Peninsulas are at their highest point in years, with the pace of both Kim’s weapons tests and combined military exercises involving the United States, South Korea and Japan intensifying in a tit-for-tat cycle. The Koreas also have engaged in Cold War-style psychological warfare that involved North Korea dropping tons of trash on the South with balloons, and the South broadcasting anti-North Korean propaganda with its loudspeakers.

South Korea’s military said soldiers fired warning shots to repel North Korean soldiers who temporarily crossed the land border Tuesday for the second time this month. The South’s military said North Korean has been increasing construction activity in front-line border areas, such as installing suspected anti-tank barriers, reinforcing roads and planting land mines.

Putin has continuously sought to rebuild ties with Pyongyang as part of efforts to restore his country’s clout and its Soviet-era alliances. Moscow’s ties with North Korea weakened after the 1991 Soviet collapse. Kim Jong Un first met with Putin in 2019 in Russia’s eastern port of Vladivostok.

After North Korea, the Kremlin said Putin will also visit Vietnam on Wednesday and Thursday for talks that are expected to be focused on trade. The United States, which has spent years strengthening ties and accelerating trade with Vietnam, criticized Putin’s planned visit.

“As Russia continues to seek international support to sustain its illegal and brutal war against Ukraine, we reiterate that no country should give Putin a platform to promote his war of aggression and otherwise allow him to normalize his atrocities,” a U.S. Embassy spokesperson in Vietnam said in a statement.

(AP)